This invention relates generally to the art of test instruments and accessories therefore, and more particularly concerns probes for electrical test instruments.
Virtually all instruments which test the condition of electronic components and/or circuits, such as VOM meters, oscilloscopes, and transistor checkers, use test probes, which act as an interface between the element or circuit point to be tested and the test instrument.
Typically, such test probes are somewhat elongated and include an insulated case or body which the operator holds, and an electrode, usually in the form of a small exposed tip, which is connected to a test lead. The test lead in turn is connected to the test instrument. In operation, the electrode is guided by the operator to the point in the circuit or to the component which is to be tested.
In many applications, however, conventional test probes are either inconvenient to use or even unsuitable. They are often too bulky to use with crowded circuits and often cause shorting when they contact other circuit points. Some probes have been provided with extended tips but these probes have been found to be cumbersome to operate and, because of their length, are inconvenient to store when not in use and are susceptible to breakage and/or damage. Furthermore, it has been found that conventional probes are susceptible to corrosion, which alters the signals being measured and thus impairs the accuracy of the total measuring system.
Accordingly, it is a general object of the present invention to provide a probe for electrical test instruments which overcomes the disadvantages of the prior art discussed above.
It is another object of the present invention to provide such an instrument probe having an electrode which may be conveniently extended and retracted from a probe body.
It is a further object of the present invention to provide such an instrument probe having an electrode which can be safely and conveniently used in a very cramped circuit environment, yet is compact for storage.
It is an additional object of the present invention to provide such an instrument probe which is safe for the operator to use.
It is yet another object of the present invention to provide such an instrument probe which does not alter or disguise the signal or other circuit condition being measured.
It is a still further object of the present invention to provide such an instrument probe having an extendible/retractable electrode which may be conveniently and reliably clamped in position.
It is an additional object of the present invention to provide such an instrument probe which is convenient to manufacture and simple to use.
It is yet another object of the present invention to provide such an instrument probe having an electrode which comprises a material which is non-corrosive, capable of holding a sharp point over an extended period of time, and which rebounds to its original configuration after any pressure thereon is relieved.